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From: tmkk@uiuc.edu (K. Khan)
Subject: Re: Ray tracing
Message-ID: <1991Jun27.184538.6963@ux1.cso.uiuc.edu>
Sender: usenet@ux1.cso.uiuc.edu (News)
Organization: University of Illinois at Urbana
References: <383@bibsyst.UUCP> 
Date: Thu, 27 Jun 1991 18:45:38 GMT
Lines: 19


In article <383@bibsyst.UUCP> ingar@bibsyst.UUCP (ingar) writes:
>I'm not sure i made myself clear the last time so I try again.
>
>In my ray tracing program I am not able to ray trace cubes, or anything
>that contains a strait line. They always end up looking like deformed 
>spheres, a sphere with angels as a matter of fact. If i ray trace an 
>object in a room the walls alway ends up in looking like "bowls". 
>I have checked my types and they are all correct, and I have checked
>that all my vector lengths are correct.
>
>Does anybody have an idea of what I am doing wrong, except the fact
>that I started to make a ray traceing program??

Here's a wild guess: check the focal length parameter in your projection
formulas. Too short a focal length value will give a fish eye lens look
to the scene, and cause the distortions you describe.